Abstract

Entamoeba histolytica produces, in axenic culture, the monocytes locomotion inhibitory factor (MLIF), a oligopeptide with selective anti-inflammatory properties. We evaluated the effect of MLIF on the expression of pro- and anti-inflammatory cytokines in CD4+ T lymphocytes from children with asthma and allergic rhinitis. Twelve children with severe asthma, 12 children with allergic rhinitis and 6 healthy controls were recruited for this study between May and December 2016. CD4+ T cells were cultured for 24 h at 37°C, 5% CO2 in the presence of MLIF, 1-phorbol 12-myristate 13-acetate (PMA), MLIF+PMA or RPMI. Interleukin-10 (IL-10), IL-4, interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) expression levels were measured in the supernatants of T-cell cultures using the enzyme-linked immunosorbent assay (ELISA). Pro- and anti-inflammatory cytokines were inhibited by MLIF (IFN-γ p=0.0036, TNF-α p<0.001, IL-4 p=0.0082) in asthmatic patients, however IFN-γ was not significantly inhibited (NS) in patients with allergic rhinitis when compared to the RPMI group. In CD4+ T cells treated with PMA+MLIF, the expression levels of IFN-γ, TNF-α and IL-4 were strongly inhibited (p<0.001, p<0.001 and p<0.0094), compared to PMA treatment alone, for both, rhinitis and asthma. IL-10 expression was not affected by MLIF in neither of the two diseases. We conclude that MLIF alters the pro/anti-inflammatory balance and induces inhibition of IL-4, IFN-γ and TNF-α, but does not affect IL-10.

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